A little (purely cosmetic) bug in foo_pqview: the filter dropdown behaves strangely if fb2k is set to be partially transparent (0.9RC under XP).
To reproduce:
Open preferences and set transparency to something other than disabled (either in Default UI or in Columns UI)
Restart fb2k
Go to Playback -> Playback queue viewer
Click the (blank) filter list to pull it down
It will bring down a rectangle that affects the area underneath the dialogue box (in Columns UI, it shows a bit of the window behind fb2k; in Default UI it does stranger things).
Again, this is a tiny bug and doesn't affect the operation of this very useful component.